Apple users trust their iPhone, Mac, and Apple Watch to keep their private data safe. But in 2023, researchers found a vulnerability—CVE-2023-32400—that threatened that trust. This issue affected iOS, iPadOS, watchOS, and macOS Ventura. In this post, we’ll explain what the vulnerability was, how attackers could exploit it, why it mattered, and how Apple fixed it. We're also providing code snippets for developers and links to official sources.

Understanding CVE-2023-32400

CVE-2023-32400 is a privilege escalation vulnerability discovered in various Apple operating systems. The main problem was in the way entitlements and privacy permissions were handled. Normally, when one app gets access to something sensitive (like your contacts, photos, or camera), only that app should hold the permission. But due to improper checks, a malicious app could potentially access or use entitlements and privacy permissions already granted to another app.

Severity: Moderate  
Discovered: Early 2023  
Patched in:

The Technical Details

In simple terms, Apple apps use “entitlements” to request access to specific resources (think “keys” for location, contacts, or camera). These requests are handled by the operating system, which checks if an app is authorized.

Here’s what went wrong

- Malicious apps could leverage entitlements and privacy permissions that were already granted to a legitimate app.

This happened because the OS did not properly isolate the permissions between different apps.

- A more precise technical guess: a malicious app could trick the OS into giving it access to data or actions it shouldn’t have, just because another app already got it legitimately.

Let’s look at a simplified code snippet to show how permissions are usually managed (not actual exploit code, but an illustration):

// App requests camera permission
import AVFoundation

AVCaptureDevice.requestAccess(for: .video) { response in
    if response {
        print("Access granted")
    } else {
        print("Access denied")
    }
}

In the vulnerable situation, a malicious app might leverage already-granted permissions from another app, bypassing the proper user endorsement.

Exploit Scenario

Let’s say you’ve installed a trusted photo app that has permission to access your camera and photos. But another, malicious app on your device could piggyback on those permissions, as they weren’t properly “checked” and isolated.

Trusted app requests and is granted permission to access the camera.

2. Malicious app on the same device uses a loophole in privacy permissions management due to missing OS checks.
3. Malicious app accesses the camera or other sensitive data without explicit approval from the user.

The Fix

Apple’s fix: Improved validation. The OS now correctly checks and enforces that app-specific entitlements and permissions can only be used by the app that owns them. No more sharing—accidental or malicious.

Apple’s note in their release iOS 16.5 security content:
> "Entitlements and privacy permissions granted to this app may be used by a malicious app. This issue was addressed with improved checks."

How to Stay Safe

- Update your OS: Make sure you’re on iOS 16.5, iPadOS 16.5, watchOS 9.5, or macOS Ventura 13.4 or later.

Watch what you install: Be careful with apps that ask for lots of permissions.

- Review app permissions: Regularly check which apps have access to your camera, contacts, microphone, etc.

References

- Apple Security Updates for iOS 16.5
- Apple Security Updates for macOS Ventura 13.4
- NIST NVD entry for CVE-2023-32400

Conclusion

CVE-2023-32400 is a reminder that even reputable systems can have privacy and security flaws. Apple acted quickly to patch this bug, ensuring that only the right apps can access the permissions you grant. If you haven’t updated your Apple devices to the latest OS version, do it now to stay secure.

If you want technical advice on coding for entitlements and permissions securely, check out Apple’s documentation on App Privacy and User Permissions.

Timeline

Published on: 06/23/2023 18:15:12 UTC
Last modified on: 09/06/2023 08:15:43 UTC